Since Sunday, the storm has parked itself over the region, pounding residents with historic rainfall amounts.

Dramatic Images Show Flood Rescues Across Houston

People being rescued by boat in Dickinson, Texas. #khou11 #Harvey Credit: @KevinReeceWFAA

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People being rescued by boat in Dickinson, Texas. #khou11 #Harvey Credit: @KevinReeceWFAA

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Rainfall so historic, in fact, the National Weather Service has had to update their color maps to measure rainfall: they simply didn't have an existing color to visualize just how much rain has fallen.